Details

Autor(en) / Beteiligte

• Rantala, Sanna
• Tikkanen, Mikko

Titel

Phosphorylation‐induced lateral rearrangements of thylakoid protein complexes upon light acclimation

Ist Teil von

• Plant direct, 2018-02, Vol.2 (2), p.e00039-n/a

Ort / Verlag

England: John Wiley & Sons, Inc

Erscheinungsjahr

2018

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Understanding the mechanistic basis of balanced excitation energy distribution between photosystem II and photosystem I (PSII and PSI) requires detailed investigation of the thylakoid light‐harvesting system composed of energetically connected LHCII trimers. The exact mechanisms controlling the excitation energy distribution remain elusive, but reversible phosphorylation is known to be one important component. Here, we addressed the role of grana margins in regulation of excitation energy distribution, as these thylakoid domains host all the complexes of photosynthetic light reactions with dynamic response to environmental cues. First, the effect of detergents for the thylakoid membrane connectivity is explained. We show that a specific interaction between the separate LHCII trimers as well as between the LHCII trimers and the PSII and PSI–LHCI complexes is a prerequisite for energetically connected and functional thylakoid membrane. Second, we demonstrate that the optimization of light reactions under changing light conditions takes place in energetically connected LHCII lake and is attained by lateral rearrangements of the PSII–LHCII and PSI–LHCI–LHCII complexes depending especially on the phosphorylation status of the LHCII protein isoform LHCB2. One sentence summary Reversible phosphorylation of LHCB1 and LHCB2 proteins is demonstrated to optimize the dynamics of the functional unit of the photosynthetic light reactions at grana margins.